The present invention relates to a component, in particular a fuel line or a fuel distributor, for a fuel injection system. The present invention further relates to a fuel injection system that is preferably used as a fuel injection system for mixture-compressing, spark-ignited internal combustion engines. The present invention specifically relates to the field of fuel injection systems of motor vehicles in which fuel is injected directly into the combustion chambers of an internal combustion engine.
A fuel distributor rail for an internal combustion engine is known from EP 2 789 845 A1. Here, reference is made to the requirements that in the course of a performance increase at a constant or reduced displacement the discharge pressures increase, that an increase in the wall thickness takes place to ensure sufficient operational reliability, and that the available installation space remains the same, however. The individual components of the fuel distributor rail are further coupled to one another at 500° C. to 1150° C. with the aid of a high-temperature soldering process. This is why at least the distributor tube of the known fuel distributor rail is formed from a duplex steel made of preferably 0.1 weight percent to 5 weight percent of nickel, preferably 20 weight percent to 25 weight percent of chromium, and preferably 2.50 weight percent to 3.50 weight percent of molybdenum. Here, materials having material numbers 1.4462, 1.4162, 1.4362, and 1.4662 are used, in which a higher strength remains even after hard soldering.
The fuel distributor rail known from EP 2 789 845 A1 has the disadvantage that in the case of the above-mentioned materials an expansion coefficient or the modified expansion behavior of the fuel distributor rail may require essential constructive adaptations. Moreover, during the manufacturing the issue of poor machinability arises.
The component according to the present invention having the features of Claim 1 and the injection system according to the present invention having the features of Claim 10 have the advantage that an improved design and functionality are enabled.
With the aid of the measures listed in the subclaims, advantageous refinements of the component indicated in Claim 1 and the injection system indicated in Claim 10 are possible.
At least the base body of the component is formed from a material that involves an austenitic or a martensitic material. A rust-proof austenite is preferably selected. A high strength is achieved as a result of grain stabilization. This, for example, enables an increase in a fluid pressure, which the fluid to be injected is subjected to, in the case of a constant or comparable geometry of the base body. A geometric adaptation, such as an increase in the wall thickness of the base body, may thus potentially be dispensed with. The increased strength may, however, also be used in a different manner. For example, a pressure increase may be enabled, while maintaining or even reducing the weight of the component. Furthermore, the material may be advantageously selected in such a way that a comparable expansion coefficient of the material results, as in the case of a conventional design.
Specifically, the component, in particular the base body, may be designed with reference to a system pressure that is greater than 35 MPa (350 bar). Such a design in particular relates to the application of a fuel injection system for gasoline or mixtures containing gasoline. It is then particularly advantageous if a refinement according to Claim 2 is implemented.
Advantageous possibilities of achieving grain stabilization of the material are indicated in Claims 3 and 4. Specifically in this case, a design may be implemented that prevents the formation of coarse grain in the temperature range of a hot shaping, as is indicated in Claim 5. This is then advantageous, in particular, in the case of a design according to Claim 6, which in particular illustrates an advantageous application in a forged fuel distributor rail. In contrast to a conventional design based on a material having the material number 1.4301, coarse grain formation may then be reduced. The provided design also results in an improved vibration resistance.
The microalloy for grain stabilization, which is preferably based on niobium and/or vanadium and/or titanium and/or aluminum, may preferably have a portion of approximately 0.005 weight percent to approximately 3.00 weight percent of the material overall. In this case, approximately 0.005 weight percent to approximately 2.50 weight percent of niobium, particularly preferably 0.008 weight percent to 0.8 weight percent of niobium, and/or approximately 0.005 weight percent to approximately 2.50 weight percent of vanadium, particularly preferably 0.008 weight percent to 0.8 weight percent of vanadium, and/or approximately 0.005 weight percent to approximately 1.50 weight percent of titanium, particularly preferably 0.008 weight percent to 0.8 weight percent of titanium, and/or approximately 0.005 weight percent to approximately 2.00 weight percent of aluminum, particularly preferably 0.008 weight percent to 0.8 weight percent of aluminum may be predefined.
One advantageous embodiment of the component is further indicated in Claim 7 that may be advantageously implemented by forging. In addition or alternatively, a grain stabilization may also be advantageous in other heat treatments, in particular in the case of hardening according to Claim 8. A selection of possible materials is indicated in Claim 9.
As a result of the grain stabilization, a light design of a component may thus, in particular, be implemented or maintained if high pressures or greater pressures, in particular pressures of more than 35 MPa, are to be implemented. Specifically, the development of a finer grain in the structure, for example as a result of a microalloy, advantageously has an effect on the resulting vibration resistance due to the higher strength, while having improved ductility at the same time. A reduction of the dimensions of the component and/or a lighter design of the component may be potentially enabled even at higher system pressures.
Preferred exemplary embodiments of the present invention are explained in greater detail in the following description with reference to the appended drawings in which corresponding elements are provided with matching reference numerals.
Fuel distributor 2 is used to store and distribute the fluid to injectors 7 through 10 designed as fuel injectors 7 through 10 and reduces pressure fluctuations and pulsations. Fuel distributor 2 may also be used to dampen pressure pulsations which may occur when fuel injectors 7 through 10 are switched. During operation, high pressures p may occur at least temporarily in an interior 11 of component 3 in this case. High-pressure line 5 includes a high-pressure input 12 and a high-pressure output 12′, which may be potentially switched, as well as a base body 13.
Fuel distributor 2 includes a tubular base body 14 that may be manufactured by forging, for example. At tubular base body 14, a high-pressure input 15 and multiple high-pressure outputs 16 through 19 are provided. Furthermore, a high-pressure terminal 20 is provided at tubular base body 14. In this exemplary embodiment, tubular base body 14, high-pressure input 15, high-pressure outputs 16 through 19, and high-pressure terminal 20 are formed from a forged single part 14′. High-pressure input 15, high-pressure outputs 16 through 19, and high-pressure terminal 20 are thus forged at base body 14.
Fuel line 5 is connected at its high-pressure input 12 to high-pressure pump 4 and at its high-pressure output 13 to high-pressure input 15 of fuel distributor 2. Fuel injectors 7 through 10 are each connected to high-pressure outputs 16 through 19 of fuel distributor 2. Furthermore, a pressure sensor 21 is provided that is mounted at high-pressure terminal 20. At an end 22, tubular base body 14 is closed by a closure 23 designed as a closing screw 23.
In tubular base body 14, a bore 24 is formed after the forging to form interior 11. Via interior 11, the fluid supplied at high-pressure input 15 may be distributed to fuel injectors 7 through 10 connected at high-pressure outputs 16 through 19.
A component 3, 3′, in particular a base body 13, 14, is preferably designed in such a way that a possibly homogenous structure 30B results that is grain-stabilized, as is illustrated in
The present invention is not limited to the described exemplary embodiments.
Number | Date | Country | Kind |
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10 2019 216 523.0 | Oct 2019 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2020/076909 | 9/25/2020 | WO |